AimTo study the changes of serum level of interleukin-1β(IL-1β), interleukin-1 receptor antagonist(IL-1Ra) and IL-1Ra/ IL-1β ratio in the patients with intracranial and extracranial atherosclerosis (As) and arterial stenosis(AS) as well as the relationship between IL-1β and IL-1Ra level.MethodsThe serum levels of IL-1β and IL-1Ra were detected in 30 patients of As, 30 AS and 30 healthy individuals by enzyme-linked immunosorbent assay and IL-1Ra/ IL-1β ratio were calculated.ResultsCompared with the control, the IL-1β level in patients with As and AS was significantly higher, but the IL-1Ra level and IL-1Ra/ IL-1β ratio was significantly lower.The levels of serum IL-1β,IL-1Ra in AS group had no difference compared with As group(p>0.05),but the IL-1Ra/IL-1β ratio was significantly lower(p<0.05).There was correlation between IL-1β and IL-1Ra levels in patients with AS and healthy, but there was no correlation between IL-1β and IL-1Ra levels in patients with As. ConclusionsThe IL-1β might accelerate the progress of As, but IL-1Ra might suppress it.The immune maladjustment of IL-1β and IL-1Ra might be correlative to the severity of As, and the IL-1Ra/ IL-1β ratio might be an available index for the severity of As.